Control method for prostehetic devices

• US 5,458,655 A
• Filed: 07/26/1994
• Issued: 10/17/1995
• Est. Priority Date: 08/31/1992
• Status: Expired due to Fees

• Current Assignee: The United States Of America As Represented By The National Aeronautics And Space Administration
• Original Assignee: The United States Of America As Represented By The National Aeronautics And Space Administration
• Inventors: Bozeman, Richard J. Jr.
• Primary Examiner(s): Willse, David H.
• Application Number:
  US08/283,474
• Time in Patent Office: 448 Days
• Field of Search: 623/24, 623/25, 623/58, 623/63, 623/64, 623/62, 623/60
• US Class Current: 623/24
• CPC Class Codes: A61B 5/1121 Determining geometric values, e.g. centre of rotation or angular range of movement
• CPC Class Codes: A61B 5/1125 Grasping motions of hands
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61F 2/585 Wrist joints
• CPC Class Codes: A61F 2/586 Fingers
• CPC Class Codes: A61F 2/72 Bioelectric control, e.g. myoelectric
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control

Abstract

A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the moveable body part through the full-shrug position of the moveable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the moveable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective moveable prosthesis device and its sub-prosthesis.

Claims

1. A method for controlling a prosthetic device, the prosthetic device comprising a plurality of moveable sub-prostheses and incorporating any implementation of harness and shoulder control hardware such that the shoulder shrug control movement associated with a moveable body part ranging from the no-shrug position of the moveable body part through the full-shrug position of the moveable body part provides control by the user to the prosthetic device, the method for controlling the prosthetic device comprising the steps of:

(a) receiving the movement from the body part,

(b) generating a sensing signal in consonance with the movement of the body part,

(c) linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part,

(d) normalizing the linear signal to be a function of the entire range of body part movement from the no-shrug position of the moveable body part through the full-shrug position of the moveable body part,

(e) dividing the normalized signal into a plurality of discrete command signals, and

(f) implementing the plurality of discrete command signals for driving a respective one of said plurality of moveable sub-prostheses of the prosthetic device.

2. A method for controlling a prosthetic device as defined in claim 1 wherein said step of dividing the normalized signal into a plurality of discrete command signals further comprises providing sustained linear commands.

3. A method for controlling a prosthetic device as defined in claim 2 wherein the step of providing sustained linear commands further comprises the step of dispensing sequential sustained linear commands.

4. A method for controlling a prosthetic device as defined in claim 2 wherein the step of providing sustained linear commands further comprises the step of dispensing non-sequential sustained linear commands.

5. A method for controlling a prosthetic device as defined in claim 1 wherein said step of dividing the normalized signal into a plurality of discrete command signals further comprises providing unsustained linear commands.

6. A method for controlling a prosthetic device as defined in claim 5 wherein the step of providing unsustained linear commands further comprises the step of dispensing sequential unsustained linear commands.

7. A method for controlling a prosthetic device as defined in claim 5 wherein the step of providing unsustained linear commands further comprises the step of dispensing non-sequential unsustained linear commands.

8. A method for controlling a prosthetic device as defined in claim 1 wherein said step of dividing the normalized signal into a plurality of discrete command signals further comprises providing sustained logarithmic commands.

9. A method for controlling a prosthetic device as defined in claim 8 wherein the step of providing sustained logarithmic commands further comprises the step of dispensing sequential sustained logarithmic commands.

10. A method for controlling a prosthetic device as defined in claim 8 wherein the step of providing sustained logarithmic commands further comprises the step of dispensing non-sequential sustained logarithmic commands.

11. A method for controlling a prosthetic device as defined in claim 1 wherein said step of dividing the normalized signal into a plurality of discrete command signals further comprises providing unsustained logarithmic commands.

12. A method for controlling a prosthetic device as defined in claim 11 wherein the step of providing unsustained logarithmic commands further comprises the step of dispensing sequential unsustained logarithmic commands.

13. A method for controlling a prosthetic device as defined in claim 11 wherein the step of providing unsustained logarithmic commands further comprises the step of dispensing non-sequential unsustained logarithmic commands.